Miniemulsion Raft Living Polymerization Preparation And Properties Of Elastomer Material

In this paper,6 chain transfer agent were used to synthesis well-defined novel copolymers.2 AB type diblock copolymers and 4 ABA type triblock copolymers of styrene and n-butyl acrylate(BA) were prepared in nanoreactor of miniemulsion using reversible addition-fragmentation chain transfer(RAFT) polymerization. The structure of the copolymers were characterized by FT-IR and the molecular weight and molecular weight distribution were characterized by GPC analysis, the dynamic light scattering (DLS) was used to characterize the size of the nanoparticle. The breaking strength, elongation and other mechanical properties were measured too.(1) The chain transfer agent BSSE and DCATC were used respectively to prepare styrene, styrene/maleic anhydride(MAh), styrene/acrylonitrile (AN) or styrene/methyl methacrylate (MAA) copolymer in miniemulsion and they followed the rule of the living radical polymerization. Then, the PS miniemulsion was used as seed emulsion, adding the second monomer BA, swelling for 24 hours and AB type copolymer was formed successfully in the RAFT miniemulsion polymerization. The relationship among the molecular weight, the breaking strength and the elongation was investigated and found that the higher molecular weight of the soft segment, the bigger of the elongation was, the biggest was 635%.(2) The chain transfer agent DBTTC, TSA and EHBIET were used respectively to prepare styrene, styrene/maleic anhydride(MAh) and styrene/acrylonitrile (AN) copolymer in miniemulsion. Some kinetic process of theirs were studied and found they followed the rule of the living radical polymerization. Two-step method was used in the miniemulsion and synthesized the triblock copolymer successfully, both ends with the hard segment (PS) and the middle with the soft segment (PBA). And the influence of the molecular weight on the elastic mechanical properties of materials was investigated. We found that if the total molecular weight was definite, when the molecular weight of the hard and was closed to the one of the soft segment, the breaking strength was maximal. The biggest breaking strength was 8.7Mpa.